British Airways must not rest on its laurels - despite its much improved profitability - according to outgoing chief executive Rod Eddington.

"The lessons for all of us at BA are simple - you can never declare victory because it's never over," he said at the UK flag carrier's investor day.

"For those of us who are still in the game it is a never ending struggle and you sow the seeds of your demise in the good times.

"Because if you think that because your numbers are looking better that you can rest on your laurels, and assume that your competitors will do the same, you are doomed to failure."

Mr Eddington, who will be succeeded as CEO by Willie Walsh, the former chief executive of Aer Lingus, outlined BA's business plan for the next two years.

The plan has three key elements - the 'Fit for Five' programme to prepare for the airline's move to the new fifth terminal at Heathrow, more investment in products and people, and a more competitive cost base.

"We're in the business of delivering service that matters for people who value how they fly," Mr Eddington added.

"We know to do that we must have a competitive cost base, but we need to do more than just have a competitive cost base. We truly need to understand our customers better than our competitors so we can invest in the right things, we need to have the best UK-based network, we need as a company to work as one team, and we need a powerful brand that people know and trust."

For the year to March 31, BA is forecasting a three to 3.5 per cent improvement in revenue.

John Rishton, the airline's finance director, said BA's fuel costs are expected to rise by £300 million next year, based on current oil prices.

Meanwhile, bmi has confirmed it will be starting three-times-a-week services between Heathrow and Riyadh from mid-summer.

Earlier this year, sole UK to Saudi operator British Airways said it would cease its flights to Riyadh and Jeddah from the end of March.

BMI also announced it would be launching four-times-a-week services between Heathrow and Mumbai (formerly Bombay) on May 14.

Chief executive Nigel Turner said: "We are of course delighted to be confirming the launch date of the first-ever BMI long-haul services from Heathrow, as well as the addition of another key destination to be served shortly afterwards.

"This is a great opportunity for London travellers to experience, for the first time on long-haul flights, the whole range of service benefits and competitive fares that bmi has built its reputation on."